Gas-drive jet pump



May 1,1962 D. G. ELLIOTT I 3,031,977

GAS-DRIVE JET PUMP Filed Feb. n2.4, 1959 7 Sheets-Sheet 1 Two PHASE M/XER SEPARAIUR `12N-'FUSER 5 j INV EN 1 OR.

May 1, 1962 D. G. ELLIOTT GAS-DRIVE JET PUMP '7 Sheets-Sheet 3 Filed Feb. 24, 1959 May 1, 1962 D. G. ELLIOTT 3,031,977

GAS-DRIVE JET PUMP Filed Feb`.- 24, 1959 '7 Sheets-Sheet 4 -mlunmmlm Madan, @e/infame@ :Qd/Mum and Wydd,

May l, 1962 D. G. ELLIOTT 3,031,977

` GAS-DRIVE JET PUMP Filed Feb. 24, 1959 '7 Sheets-Sheet 5 t HIGH PESSURE 257%57 uw www@ 250 27a 276 256eL 272 :7" 2:/

DRIVE GAS DRIVE FLUID Low PRESSURE sucrlon/ FLUID Low Pzsssues I 560.e 1 3 i* Od 50564 3 370 n 350g ff g l of l 566 fggl is DE/VEL/QU/D SEPARATOR D DIFFUSER NOZZLE M/XEQ INVENTOR. DA V/D G. ELL/OTT 4 fro/2 May 1, 1962 D. G. ELLIOTT 3,031,977

GAS-DRIVE JET PUMP Filed Feb. 24, 1959 7 Sheets-Sheet 6 INVENTOR. Dm//D C?. ELL/07'7- Arron/5K5.

7 Sheets-Sheet 7 Filed Feb. 24, 1959 904) L/Qu/D TWO PHASE *SEPA/170i? l NOZZLE 'P MIXER l'. DIF/:USER` NOZZLE *GAS Two PHASE .n M/XER D/FFUSER SEHARATUR D/F/-UsE/' NOZZLE NSER -P SEPA/MWI? -b D/F'F'USER LIQ INVENTOR. DAV/D G. ELL/07'7- United States Patent() 3,031,977 GAS-DRIYE JET PUMP David G. Elliott, West Lafayette, Ind. (3526 Paraiso Way, La Crescenta, Calif.) Filed Feb. 24, 1959, Ser. No. 795,245 25 Claims. (Cl. 103-258) The present invention relates to a pump and, in particular, to a gas-drive jet pump having particular utility in supplying liquids to a rocket engine.

In the missile and rocket field, liquid and solid fuel propellants are now being used to drive rocket motors which are the thrust producing components of rocket engines. These rocket motors are known to consume large quantities of the liquid propellants consisting of a liquid fuel, i.e., alcohol or gasoline, and a liquid oxidizer, i.e., liquid oxygen or nitric acid. The propellents are stored separately in tanks pressurized to about 50 p.s.i.a. and must be fed to the rocket motor at pressures ranging from 300 p.s.i.a. to 1000 p.s.i.a. In order to increase the pressure of the liquid propellants, it is customary to use a high pressure drive gas generated chemically from one or both of the liquid propellants or from a separate chemical source.

A few of the basic types of pumps applicable to rocket engines will now be discussed so that the exact nature and operation of the gas-drive jet pump embodying the principles of the present invention can readily be understood. Broadly speaking, pumps can be categorized into either of the following two classes: Class l-work is done on a suction liquid by solid objects which move with and exert a force on the uid, for example, mechanical gear type, vane type or piston type pumps fall into this category; Class 2-work is done on a suction liquid by a drive fluid which mixes with and shares its momentum with the suction liquid. The Class 2 pumps can be furi ther classified into two subclasses according to the relajtive magnitudes of the drive pressure of the drive fluid,

j the suction pressure of the suction liquid, and the discharge pressure of the suction liquid leaving the pump, e.g., 2athe discharge pressure of the suction liquid is less than the drive pressure of the drive fluid; and, Zb-the discharge pressure of the suction liquid is equal to or greater than the drive pressure of the drive fluid.

The most descriptive general title for Class 2 pumps is jet pump. An example of a prior art Class 2a pump is an ejector, while an example of a prior art Class 2b pump is an injector The gas-drive jet pump, which is the subject of the present application, is a class 2b type pump since the suction liquid can be pumped to a discharge pressure which is equal to or greater than the drive pressure ofthe drive fluid.

Other types of Class 2b pumps are as follows: (l) the injector, (2) gas-drive booster pump of the type described in French Patent No. 809,570, and (3) a single phase gas-drive jet pump. Considering now each of these pumps individually for the purpose of clearly comparing these pumps with the gas-drive jet pump, the injector uses a high pressure drive fluid to pump a suction liquid to a pressure equal to or greater than the pressure of the steam. In its only practical applications, the injector has been used to pump water by using steam as the drive fluid. The mechanism employed includes a drive nozzle, a mixer, a condenser, and a diffuser. The drive steam or vapor enters the drive nozzle at a drive pressure and is accelerated to a high velocity as it expands in the nozzle to the suction pressure. The suction liquid, i.e., water, enters the mixer at its suction pressure and is mixed with the drive steam. As the mixing progresses, the suction liquid accelerates and the drive steam decelerates. At the same time, the suction liquid (water) absorbs heat from the drivesteam and the steam begins to cool and con ICC dense. This condensation occurs in the condenser so that at the exit of the condenser all of the steam is condensed to Water. The water then enters a diffuser where it is decelerated and the dynamic pressure of the water converted to a static discharge pressure. The discharge pressure of the water can be higher than the drive pressure of the steam because the mixture of the suction liquid (water) and the drive steam undergoes a large density increase when the drive steam condenses in the condenser. As a result, even though the water reaching the diffuser has a velocity less than that of the drive steam, the dynamic pressure of the mixture is greater than the pressure of the drive steam. The injector cannot be used satisfactorily as a propellant pump for a rocket motor because rocket propellents do not have enough heat capacity to condense the amounts of vapor required for pumping propellants to the high pressures required in a rocket motor.

The gas drive booster pump includes a drive nozzle', a separator and a diffuser, and is able to pump any suction liquid by the use of a drive fluid such as a gas or a vapor which at the most only partially condenses when mixed with the suction liquid. In a gas-drive booster pump, however, the suction liquid must be supplied to the purnpv at a pressure equal to the drive pressure of the drive gas. Specifically, the drive gas and suction liquid enter the drive nozzle and the resulting mixture is accelerated to a high velocity as it expands to a lower pressure in the drive nozzle. The high velocity liquid and gas mixture enters the separator where the gaseous portion of the mixture is separated from the liquid portion and is discharged to the atmosphere. The liquid traveling at a high velocity coalesces into a liquid jet and enters the diffuser wherein the dynamic pressure of the liquid is converted to static discharge pressure. This pressure can be considerably higher than the drive pressure of the drive gas since the liquid jet entering the diffuser has a much higher density, although the same velocity as the liquid and gas mixture leaving the drive nozzle. The gas drive booster pump cannot be used by itself as a propellant pump for a rocket motor since the suction liquid must be at a high pressure when supplied to the pump.

The single phase gas-drive jet pump embodies a drive nozzle, a mixer, a separator and a diffuser and pumps a suction liquid by use of a drive iiuid comprising any gas or vapor which does not condense when mixed with the suction liquid. The drive gas enters the drive nozzle at a drive pressure and is accelerated to a high velocity as it expands to the pressure of the suction liquid. The suction liquid enters the mixer at the suction pressure and mixes with a jet of drive gas, so that the resulting mixture of liquid and gas leaves the mixer at a high velocity which is slightly less than the velocity with which the drive gas left the drive nozzle. The high velocity liquid and gas mixture enters the separator where the gas is separated from the liquid and discharged to the atmosphere. The separated liquid, traveling at a high velocity, coalesces into a liquid jet prior to its entry into the diffuser. In the diffuser the dynamic pressure of the liquid is converted to a static discharge pressure which can be equal to or greater than the drive pressure of the' drive gas. The explanation for this condition is the same' as in the case of the injector, i.e., the liquid entering the diffuser although it has a lower velocity than the drive gas leaving the drive nozzle, is suiciently denser than the drive gas to make the dynamic pressure of the liquid greater than the drive pressure of the drive gas leaving the drive nozzle. The only basic difference between theV single phase gas drive jet pump and the injector is the method of producing the density increase. For example, in the single phase gas drive jet pump the separation of the gas from the liquid affects the increase in density while in the injector the condensation of the steam in the water jet produces the increase in density. The single phase gas drive jet pump is also unsatisfactory for use as a propellant pump for a rocket motor because of the excessive amount of gas consumption. Actually, the amount of drive gas used in a single phase drive jet pump is many times that consumed bya conventional turbopump.

It is a primary object of the present invention to provide a gas-drive jet pump which has particular utility as a propellant pump for a rocket motor but which does not embody the undesirable features inherent in the prior art pumps discussed above.

It is another object of the present invention to provide a new and improved jet pump which is comparable in performance with the existing rocket motor propellant pumps, but which is simpler, more reliable, and more economical.

It is a further object of the present invention to provide a pump which uses both a high pressure gas and a high pressure liquid as the drive medium for pumping a low pressure suction liquid to a high pressure discharge liquid.

It is yet a further object of the present invention in accordance with the previous object to use a portion of the high pressure discharge liquid as the high pressure liquid portion of the drive medium.

It is yet another object of the present invention to provide a gas-drive jet pump wherein a portion of a high pressure discharge liquid is fed back into the pump to be used as the liquid in a combined gas and liquid drive medium.

Other objects and advantages reside in the particular details of construction of the pumps characterized by the features of the present invention, and among these details might be specifically mentioned the arrangement of parts to produce a pump which has no, or most only a few, moving parts and which is, therefore, reliable, compact, light in weight, and easy to install and maintain.

The above and other objects are realized, in accordance with the present invention, by providing a new and improved gas-drive jet pump for increasing the pressure of a low pressure suction fluid by the use of a drive medium. The drive medium includesa high pressure drive gas supplied from an outside source and a high pressure drive liquid fed back from the pump discharge port. The drive gas and the drive liquid are combined at the entrance of a nozzle in such manner as to provide a substantially uniform drive medium. The drive medium flows into the drive nozzle where it expands and is accelerated to a high velocity and has its pressure lowered to that of the low pressure suction liquid. The drive medium enters a mixer where it is mixed with the suction fluid at the low pressure to provide a gas and liquid mixture having an intermediate high velocity less than the velocity of the drive medium leaving the nozzle. This mixture leaves the mixer as a high velocity stream or jet and enters a separator where the gaseous portion of the mixture is separated from the liquid and discharged to the atmosphere. The liquid in the separator travels at a high velocity and coalesces into a liquid jet which enters a diffuser. In the diffuser the mixture is decelerated and the dynamic pressure of the liquid is converted to a static discharge pressure which can be equal to or ygreater than the pressure of the drive gas. The pressure increase is achieved since, even though the liquid entering the diffuser has a lower velocity than the drive medium leaving the drive nozzle, this liquid is denser than the drive medium and, as a result, the dynamic pressure or kinetic energy of the liquid can be greater than the drive pressure of the drive medium.

The use of a drive medium comprising a liquid and a gas is a very efficient method of effecting an energy transfer to the suction liquid. The gas-drive jet pump does not inefficiently add a small quantity of drive gas at a very. high velocity to a low velocity suction liquid but instead mixes a drive gas and a drive liquid in a highly eicient expansion process and then, with relatively high efiiciency, mixes the suction liquid with the drive medium when the latter is traveling at only moderately high velocity.

The invention, both as to its organization and method of operation, together with further objects and advantages thereof, will best be understood by reference to the following detailed description taken in conjunction with the accompanying drawings, in which:

FIG. l is a cycle diagram showing the cycle of operation of several embodiments of a gas-drive jet pump characterized by the features of the present invention;

FIG. 2 is a front elevational view of an embodiment of the gas-drive jet pump employing the hydraulic cycle shown in FIG. l;

FIG. 3 is an enlarged fragmentary view of the pump of FIG. 2 shown principally in section and illustrating particularly a two-phase nozzle embodied in the pump;

FIG. 4 is an enlarged fragmentary view of the pump of FIG. 2 shown principally in section and illustrating a mixer, a separator and a diffuser embodied in the pump;

FIG. 5 is a fragmentary, sectional view taken along a line substantially corresponding to line 5-5 of FIG. 3 assuming, of course, that the latter shows the entire structure;

FIG. 6 is a sectional view taken along a line substantially corresponding to line 6-6 of FIG. 4, again assuming that the latter shows the entire structure;

FIG. 7 is a sectional view taken along a line substantially corresponding to line 7--7 of FIG. 3, assuming again that the latter shows the entire structure;

FIG. 8 is an enlarged fragmentary, sectional view taken along a line substantially corresponding to line 8-8 of FIG. 4, again assuming that the latter shows the entire structure;

FIG. 9 is an enlarged sectional view taken along a line corresponding substantially to line 9-9 of FIG. 4, aS- suming again that the latter shows the entire structure;

FIG. 10 is an enlarged fragmentary, sectional view taken along a line corresponding substantially to line 10-10 of FIG. 3;

FIG. l1 is an enlarged fragmentary, sectional view taken along a line corresponding substantially to line 11--11 of FIG. 3;

FIG. 12 is a front elevational view, shown partially broken away, of a second embodiment of the present invention employing the operating cycle of FIG. l;

lFIG. 13 is an enlarged sectional view taken along line 13-13 of FIG. l2;

FIG. 14 is a reduced sectional view taken along line 14-14 of FIG. 13. assuming, of course. that the latter shows the entire structure;

FIG. l5 is an enlarged fragmentary` sectional view taken along a. line corresponding substantially to line 15-15 of FIG. 13 making the same assumption as above;

FIG. 16 is an enlarged fragmentary, sectional view taken along a line substantially corresponding to line 16-16 of FIG. 13, assuming again that the latter shows the entire structure;

FIG. 17 is a fragmentary, sectional view taken along line 17-17 of FIG. l5;

FIG. 18 is a fragmentary, sectional view taken along a line corresponding substantially to line 18-18 of FIG. 17, again assuming that the latter shows the entire structure;

FIG. 19 is a fragmentary, sectional view taken along line 19-19 of FIG. 13, assuming again that the latter shows the entire structure;

FIG. 20 is a fragmentary, sectional view showing a third embodiment of the present invention operating on the cycle shown in FIG. l, and this view illustrates a portion of a nozzle, a mixer, a separator, and first and second diffusera;

FIG. 2l is a sectional view of a fourth embodiment of the present invention operating on the cycle shown in FIG. 1, and this view illustrates a combined nozzle and mixer;

FIG. 22 is asectional View of a fifth embodiment of the present invention operating on the cycle shown n FIG. l, and is similar to FIG. 20 but illustrates a modified mixer;

FIG. 23 is a sectional view of a sixth embodiment of the present invention operating on the cycle shown in FIG. 1, and is similar to FIG. 13 but illustrates yet another modified mixer;

FIG. 24 is a perspective view of a seventh embodiment of the present invention operating on the cycle shown in FIG. 1, and employing a rotating mixer-separator;

FIG. 25 is a sectional view taken along line 25-25 of FIG. 24;

FIG. 26 is a sectional view taken along a line corresponding substantially to line 26-26 of FIG. 25, assuming, of course, that the latter shows the entire structure; 1 FIG. 27 is a fragmentary, sectional view showing an eighth embodiment of the present invention;

FIG. 28 is an end elevationalview of the embodiment illustrated in FIG. 27;

FIG. 29 is a cycle diagram showing another cycle which might be used in the operation of the gas-drive jet pump in accordance with the present invention;

FIG. 30-is a sectional View of a ninth embodiment of the present invention operating on the cycle shown in FIG. 29 and is somewhat similar to FIG. 20 but illustrates a modified mixer;

FIG. 3l is a cycle diagram of a third operating circuit embodied in the gas-drive jet pump;

FIG. 32 is a cycle diagram of a fourth operating circuit embodied in the gas-drive jet pump; and

FIG. 33 is a cycle diagram of a fifth operating circuit embodied in the gas-drive jet pump.

Referring now to the drawings, several embodiments of the present invention are illustrated and will be described in order of illustration. However, the order of discussion should not be construed to 'be indicative of relative importance of the embodiments.

Since the pumps of the present invention, as indicated above, are particularly well suited for use in supplying liquid propellants to a rocket motor, the ensuing description will be devoted to their use in this environment. although it should be understood that the invention is not limited exclusively to this field. Considering first the lembodiment illustrated in FIGS. 2 through ll, there is shown a gas-drive jet pump 50 operating upon the cycle shown in block form in FIG. l and characterized by the features of the present invention. The jet pump 50 briefly comprises a nozzle unit 52, into which both a high pressure drive gas and a high pressure drive tiuid are admitted and combined to form a drive medium which is increased in velocity and decreased in pressure in the nozzle. The low pressure drive medium is mixed with a low pressure suction liuid in a mixer 54 and the resulting low pressure mixture passes into a separator 56 where the gas and the liquid portions of the mixture are separated, the gas being discharged to the atmosphere and the liquid portion of the mixture being directed into a diffuser 58. The liquid enters the diffuser 58 at a high velocity and low pressure and leaves the diffuser 58 as a high pressure, discharge liquid. Most of the discharge liquid leaves the pump 50 and is supplied to the rocket motor while the balance of the discharge fluid is fed back through a feedback conduit 60 to the nozzle 52.

More specifically, the high pressure drive gas, which, for example, may be the decomposition products of anhydrous hydrazine (N2H4) obtained in a chemical reaction, is supplied from a high pressure tank or gas generator (not shown) to the nozzle unit 52. Specifically, as is best shown in FIG. 3, the high pressure drive gas passes through an inlet connector 64 into a premixer 65 through an annular chamber 66 defined between a two phase nozzle 68 and a sleeve-like housing 70 secured by fasteners 72 vto the nozzle 68. The drive gas flows from the chamber 66 into a chamber 67 which communicates With Ithe mouth 68a of the nozzle through spaced openings 78a in a drive gas injection plate 78 supported in the mouth 68a of the nozzle 68. The chamber 67 is defined by the housing 70, a drive liquid manifold 80, which is supported within the left end of the housing 70 as viewed in FIG. 3, by fasteners 82, and the injection plate 78, and has a plurality of spaced apart tubes 84 extending therethrough. The tubes 84 are supported at one end within spaced apart openings 80a formed in the manifold 80 and at their free ends extend into the openings 78a in the injection plate 78. As is best shown in FIG. ll, each of the openings 78a is somewhat larger than the outer diameter of its associated tube 84, thereby defining a s-mall annular passage 84a surrounding the free end of each tube to permit the flow of drive gas from the chamber 67 to the mouth 68a of the nozzle. Corresponding ones of the openings 78a and 80a, of course, are aligned so that the tubes 84 are maintained in parallel, spaced apart relation and function -to deliver the drive liquid into the mouth 68a of the nozzle 68.

In accordance with an important feature of the present invention, a portion of the high pressure discharge liquid developed by the pump is fed back to the nozzle unit 52 through the feedback conduit 60. The high pressure discharge liquid passes from the conduit 60 to the lower branch 74a of an inlet T-connector 74, best shown in FIG. 3. The center leg 74e of the connector 74 is threadedly received within one end of the drive liquid manifold 80 to provide fluid communication between the conduit 60 and a chamber 85 opening to the left ends of all of the spaced tubes 84. Suitable sealing rings or gaskets 77, 79 and 81 may be employed to inhibit the escape of fluid from the chamber 66, 67 and 85. The high pressure discharge liquid tiows from the chamber 85, through the plurality of tubes 84 and into the mouth 68a of the nozzle 68 for mixture with the drive gas which passes into the mouth 68a of the nozzle 68 through the passages 84a in the injection plate 78 as described above. By this construction, the high pressure drive gas and drive liquid are uniformly mixed in the mouth 68a of the nozzle to form a high pressure drive medium.

The nozzle 68, as is best shown in FIGS. 5 and 10, is formed from metal stock having a square or rectangular cross section which is provided with a through nozzle passageway of circular cross section throughout but varying in diameter to define the mouth 68a, a throat portion 68b, and a diverging portion 68C (FIG. 3). The drive medium traveling at low velocity enters the mouth 68a of the nozzle and then ows to the constricted area or throat 68b. Since the walls of the nozzle 68 converge to define the throat 68b, the velocity of the drive medium passing through this converging region is increased and its pressure is decreased. The high velocity, low pressure medium then passes through the diverging portion 68e of the nozzle to the right of the throat 68b (as viewed in FIG. 3) and is discharged from the nozzle outlet 68d at a high velocity and at a pressure equal to atmospheric pressure. The pressure of the drive medium at the outlet of the nozzle unit 52 is thus reduced to the pressure of the suction liquid which is also at atmospheric pressure.

The high velocity drive medium and the low pressure, low velocity suction uid are mixed within the mixer 5-4 to produce a gas and liquid mixture having an intermediate high velocity slightly less than the velocity of the drive medium entering the mixing stage. More particularly, the suction liquid is fed to a suction liquid, wedge-shaped inlet block 87 through a conduit connected to a connector 86 threadedly secured to the inlet block. The inlet block 87 is seated on the upper iiat surface of the nozzle 68 and is held in position by a pair of vertical plates 88 and 89 (FIG. 5) which are bolted or otherwise secured to the flat, vertical side surfaces of the inlet 87 and to the side surfaces of the nozzle l the bottom of the rounder. i in position by side plates 99 (FIGS. 4 and 6) secured to 7 68. The plates 88 and 89 are further secured to an elongated mixer end plate 90 resting on the inlet block 87 and to a diEuser support 91 seated againstl the lower surface of the nozzle 68. The end plate 90 is clamped against the upper inclined surface of the block 87 by means of a pair of strips 95 and 97 respectively bolted to the side plates 88 and 89 and extending along the upper edges of the plate 90. The suction liquid enters an inlet chamber 87a (FIG. 3) formed in the block 87 and then passes through an elongated passage 93 of rectangular cross section (FIG. The passage 93 is formed by a recess 87b in block 87 and is covered by the end plate 90. This ssage opens at one end to the chamber 87a and at the other end opens into a mixing chamber 94 which is defined adjacent the outlet 68d of the nozzle. The mixing chamber 94 is bounded on its sides by a pair of vertical plates 96 and 98 (see FIGS. 3 and 6) bolted to the strips 95 and 97, respectively, and is bounded at the top by the under surface 92 of the end plate 90. The end plate 90 is inclined downwardly adjacent the exit end or outlet of the nozzle so that the drive medium leaving the nozzle is intercepted by the flat under-surface portion 92a. Thus, the nozzle outlet 68d and the exit end of the passage 93 deliver fluids to the same region in the chamber l94 in paths which are inclined slightly relative to one another. Thus, the suction liquid passes through the connector 86, cham-ber 87a, and passage 93 into the mixing chamber 94 and mixes with the drive medium owing from the nozzle over the exitend of the passage 93. When a static condition is reached the suction liquid emanating from the passage 93 flows along the surface 92a and the drive medium from the outlet of the nozzle impinges upon and mixes with the low pressure suction uid to provide a mixture of gas and liquid. The velocity of the slowing moving suction liquid is increased while the high velocity of the drive medium is slightly decreased so that the resulting gas and liquid mixture has a relatively high intermediate velocity somewhat lower than that of the drive uid leaving the nozzle. As the gas and liquid mixture proceeds along the under surface 92, it reaches the separator 56 at the lower right end 92b of the plate which is curved and tapered as shown in FIGS. 4 and 6 to cause the gas and liquidr mixture to be shaped into a small jet. More particularly, the plate 90 has tapering side edges merging to a small end 90a and, since the strips 95 and 97 follow the side edges of the plate 90, they too come together near the end 90a as is shown in FIG. 9. The curved portion 92b is of a general semi-cylindrical configuration in longitudinal section and causes the gas and liquid mixture substantially to reverse its direction of movement. As the gas and liquid mixture moves over the cylindrical surface 92h, the liquid portion of the mixture is moved by centrifugal force irnmediately adjacent the surface 92b because of its greater weight, to form a liquid jet. Actually, as the drive liquid moves toward the surface 92b it further mixes with and accelerates the suction liquid. At the same time, the lighter gas portion of the mixture remains away from the surface 92b and forms a layer of gas immediately adjacent the liquid jet. At the end of the surface 92b, as indicated at the point 97 and as shown in FIG. 9, the liquid jet has a generally inverted trapezoidal cross-section formed by the undersurface 9211 and by the plates 96 and 98 which, as shown in FIG. 9, are tapered and inclined at the curved end of the plate 90. Theeliquid `|et`vfed into a transition piece or rounder 100. The rounder 100, as shown in FIG. 8, is supported j upon the. end portion 90a of the plate 90 which is inclined or tapered to a point as indicated at 90b in FIG. 4 so that the inclined edge complements and mates with The rounder 100 is held the strips 95 and `97 and performs the function of transforming the trapezoidal-shaped jet into a circular jet in preparation for entry into the diffuser 58. To this end, the rounder includes a trapezoidal shaped inlet aperture b opening to a through passage 100e having its walls deformed to merge into a circular outlet opening 100d which is surrounded by an annular recess 100e. The layer of gas disposed on top of the trapezoidal-shaped jet is intercepted by the inclined surface 100a on the top of the rounder 100, thereby to divert the gas around the rounder and exhaust it directly to the atmosphere. It will be appreciated that the separator 56 does not affect the characteristics of the liquid jet so that the jet leaving the rounder 100 has a low pressure and a moderately high velocity.

Considering now the diffuser 58, it comprises a diffuser element 102 having a narrow tapered end 102:1 disposed within the annular recess 100e at the exit end of the rounder 100 and also having a diverging passageway 102e therethrough. The element 102 includes a portion 102b having a cylindrical outer surface end portion 4102b accommodated Within a diuser outlet block 104 xedly secured upon a mounting plate 106 attached to the diffuser support 91 as shown in FIG. 4. To facilitate the assembly of these parts, the block 104 includes an annular recess 104a.in its outer periphery for receiving the plate 106 and, to the same end, the end of the block is seated against shoulder 102d on the element formed by the flat cylindrical end portion 102b. The block 104 is provided with a through passage formed by a constant diameter portion 104b and a diverging diameter portion 104e. Thus, the walls defining the through passage in the diffuser element 102 and the walls defining the through passage in the block 104 are circular in section and cooperate to for-rn a continuous passage diverging from the exit end of the rounder 100 to the left toward the discharge outlet of the pump. By this construction, the liquid leaving the separator at a high velocity is decelerated in the diffuser 58 so that the dynamic pressure or kinetic energy of the liquid is converted into a static discharge pressure which may be equal to or greater than the pressure of the drive gas entering the fitting 64. The liquid leaving the diffuser 58 is discharged through a coupling 108 into a T-shaped tting 110, the leg 110a of which comprises an externally threaded connector adapted to be attached to a suitable discharge conduit for delivering the outlet liquid to a rocket motor or the like. The coupling 108 is, of course, threaded onto an externally threaded hub 104d on the outlet block 104.

In accordance with the present invention, the feedback conduit 60 referred to above is connected between the T-shaped fitting 110 and the inlet connector 74 for the purpose of feeding back a portion of the high pressure discharge liquid to the nozzle unit 52. As is best shown in FIG. 2, the conduit 60 includes a coupler 111 secured between the connector 110 and a check valve 112 which prevents liquid or gas flow through the check valve fror left to right, as viewed in FIG. 2. The left end of the check valve 112 is attached by a coupler 113 to the left end of an L-shaped conduit 114 which is connected by a coupling 116 to the lower branch 74a of the inlet T connector 74. By this feedback arrangement, a portion of the discharge liquid is recycled back through the pump, thereby effecting a continuous, stable and efficient pump operation.

Since the discharge liquid is not available when starting the pump, the upper branch 74b of the inlet T-connector 74 may be fed with an external high pressure drive liquid until the pump operation is initiated. The branch 74b is normally closed Aby a valve (not shown) which may be opened to permit the insertion of the external drive liquid during starting and which is closed after the pump 50 begins to function. The check valve 112, of course, prevents the passage of the external drive liquid to the exit side of the diffuser 58 with the result that the pump 50 does not have to work against the high pressure of the external source at the diffuser 58.

In the second embodiment of the present invention illustrated in FIGS. l2 through 19, a compactly arranged, generally cylindrical jet pump 1.50 is illustrated as including a manifold 151 (FIG. 13) wherein a high pressure drive gas and a high pressure drive liquid are mixed to form a drive medium which is fed into a plurality of spaced nozzles 165 extending longitudinally of the pump. The high velocity, low pressure drive medium leaving the nozzles 165 is'mixed with a low pressure suction liuid in a mixer 154 in order `to form a combined gas and liquid mixture. The gas portion is separated from the liquid portion of the mixture in a separator 156, the separated gas being discharged to the atmosphere and the separated liquid being directed into a diffuser 157 which' converts the dynamic pressure of the liquid into a static pressure which may be higher than or equal to the pressure of the drive liquid.

More specifically, a high pressure drive gas, which is generated from an external source in the manner de scribed above in connection with the embodiment of the invention shown in FIGS. 1 to ll, is fed into a connector or fitting 155 threadedly attached to a manifold block 158 The drive gas liows through a central bore 159 in the connector 155 to an annular chamber 160 defined between a sleeve 161 and a diffuser tube 162. The chamber 160 opens to a radially extending annular chamber 164 defined by the sleeve 161 and the diffuser tube 162 and by a nozzle block 167. The drive gas tiows from the chamber 164 through a plurality of incline'd passageways 166 defined in the nozzle block 167 for the purpose of connecting the chamber 164 with a plurality of slots 169 extending longitudinally of the nozzle block as shown in FIGS. 13, 17 and 18. The drive gas leaves the slots 169 as indicated by arrow pointed lines 169:1 in FIG. 18 and enters passageways 168 formed at the ends of the slots between the nozzle block 167 and an outer nozzle shell 170 with the result that the drive gas emerging from each of the slots 169 divides with a portion flowing through one of the passages 168 into the mouth 165a of one of the nozzles 165 located on one side of the slot and with another portion of the gas fiowng through the mouth 165a of another nozzle 165 located on the other side of the slot 169. As illustrated by the arrow pointed lines in FIG. 18, the drive gas issuing from the slots 169 liows along an outwardly extending annular fiange 167a formed on the nozzle block 167 to provide a drive liquid injection plate as described hereinafter. The gas passing along the flange 167a. is directed across the mouth 165a of each nozzle 165 from opposite directions and is turned into the nozzle mouth by the force of the opposing gas streams.

Considering next the liow of the high pressure drive liquids which may be supplied either from the discharge outlet of the pump 150 or from an external source, this liquid is fed into a connector or Pfitting 180 threadedly secured to the manifold block 158 as shown in FIG. 13. The drive liquid passes through a bore 181 in the connector 180 and tiows into a chamber 182 having a crescent shaped cross section as illustrated in FIG. 14 and delined between the manifold block 158 and the sleeve 161. The chamber 182 opens to an annular chamber 183 defined by the manifold block 158, the sleeve 161, the nozzle shell 170 and the nozzle block 167. The drive liquid passes out of the chamber 183 through a plurality of spaced openings`0184 defined in the annular flange 167a shown best in FIGS. 13 and 19. The liquid emerging from the openings 184 is injected directly into the mouths 165a of the nozzles 165. The openings 184 are so spaced and dimensioned that the drive gas liowing across the mouths of the nozzles 165 and across the injection opening 184 and the drive liquid flowing directly into the mouth are thoroughly mixed to provide a drive medium having a substantially uniform mixture of the drive gas and the drive liquid.

The drive medium or gas-liquid mixture fiows into the mouths 16511 of the nozzles which, as previously mentioned, extend longitudinally of the pump and are defined between the nozzle block 167 and the outer nozzle shell 170. As is best shown in FIGS. 15 and 16, each nozzle 165 has a rectangular cross section and includes a converging portion 165b interconnecting the mouth 165a with a throat 165e having a sectional area illustrated in FIG. 16. Each nozzle further has a diverging portion 165d between its throat 165e and its exit end 165e which is shown in FIG. 15. This converging-diverging contour of the nozzle 165 transforms the high pressure, low velocity drive medium into a low pressure, high velocity medium. The high `velocity fluid medium is dis charged from the ends 165e of the nozzles directly into the mixer 154 for mixture with a low pressure suction liquid.

The suction liquid at low pressure and low velocity is supplied from a source (not shown) to an inlet fitting 185 (FIG. 13) where it passes through a longitudinal bore 186 communicating with an enlarged chamber 187. The chamber 187 is connected to an annular chamber 188 by a plurality of angularly related spaced apart passageways 189, the annular chamber 188 being defined between the inlet fitting 185 and the nozzle shell and having a reverse bend portion 188a. This reverse bend portion is defined by an annular rim :1 inserted within but spaced from the walls of an annular recess 170e formed in the nozzle shell 170. The suction liquid flowing through the reverse bend portion 188a reverses direction and emerges onto a frustro-conical surface 190 provided on the inlet 185 and forming part of the mixer 154. The surface 190 is inclined across the exit ends 165e of the nozzles 165 so that the suction liquid flowing on the surface 190 is joined by the drive medium emanating from the nozzles with the result that the suction liquid and the drive medium are mixed together to form a gas and liquid mixture having an intermediate velocity considerably greater than that of the suction liquid but somewhat less than that of the drive medium issuing from the nozzles.

The gas and liquid mixture leaves the mixer 154 and enters the separator 156 which comprises a toroidal surface 192 located contiguous with the frustro-conical surface 190 and cooperating with the latter to provide a continuous smooth surface. As the gas and liquid mixture passes along the toroidal surface 192 the gas portion and the liquid portion of the mixture are separated and, in particular, the drive liquid due to its greater weight separates from the drive gas and closely hugs the surface 192. thereby further mixing with and accelerating the suction liquid. As described above, the liquid forms a layer on the surface 192 while the somewhat lighter gas forms a layer immediately on top of the liquid during the passage over the toroidal surface. The toroidal surface 192 terminates in an apex or spike 194 having a tip extending into the entrance of a diffuser element 196 secured by fasteners 197 to the diffuser support 162. The separated layer of liquid on the surface 192 forms a jet of circular section as it passes over the apex 194 and leaves the separator 156 while the gas portion forms a hollow jet surrounding the liquid as this gas approaches the apex 194. Just before the two jets reach the apex they are intercepted by the entrance end 196e of the diffuser element 196 which has a circular knife edge of a diameter equal to the diameter of the liquid jet. Accordingly, the liquid jet passes into the entrance of the diffuser element 196 while the gas is directed by the ta-I pered outer surface 196b of the diffuser element 196 into a chamber 198 defined between the nozzle block 167, the element 196 and the diffuser support 162. The chamber 198 opens to a plurality of radially extending passageways 199 defined in the block 167 and aligned with passageways 200 formed in the nozzle shell 170. The aligned passageways 199 and 200 exhaust the gas from the chamber 198 to atmosphere, the gas ow be- 1 1 ing indicated by dotted lines in FIG. 17. As shown in FIG. 18, the passageways 199 are defined between the nozzles 165 and, in particular, are located between the throats 165e` and have a generally rhombic or diamond shape complementary to the converging and diverging nozzle portions 165b and 165d.

The liquid jet as indicated above leaves the separator 156 and passes into the diffuser. 157 through the diffuser element 196 which has a gradually diverging passage 201 for transforming the dynamic pressure of the entering liquid jet into a static pressure which may be equal to or higher than the pressure of the drive medium. The high pressure liquid flows from the diffuser element 196 into an elongated passage 202 defined centrally of the diffuser support 162. The passage 202 communicates with a generally diverging passageway 203 defined in the manifold block 158 so that the high pressure discharge liquid is further decelerated before it enters a conduit (not shown) connected to a rocket motor. As in the case of the first embodiment of the invention shown in FIGS. 1 to 11, a portion of the high pressure discharge liquid may be fed back to the inlet bore 181 in the connector 180 to be used as the high pressure drive liquid.

A third embodiment of the invention is illustrated in FIG. 20 wherein there is shown a portion of a drive gas jet pump 250. The jet pump 250 embodies a nozzle 151 which is preferably identical to the nozzle'unit 52 described above, a mixer 252, a separator 254, and a primary diffuser 256. The pump 250 differs principally from the previously described two embodiments in its geometric construction and in that it also employs a secondary diffuser 257 for receiving any gas and liquid which fails to enter the primary diffuser 256. By this construction, both a high pressure discharge liquid and a low pressure discharge liquid are developed by the pump 250.

As described above in connection with the first embodiment of the invention, a drive gas and a drive liquid are mixed and accelerated in the nozzle 251 to form a drive medium. As shown, the drive medium moves to the right through the diverging portion 251e of the nozzle 251 and is intercepted by a cone 258 disposed within the discharge end of the nozzle. The cone 258 has a conical outer surface and is supported centrally of the nozzle 251 by a generally conical member 260. The drive medium leaving the nozzle flows into an outwardly flaring annular passageway 261 defined between the member 260 and a nozzle block 263.

The low pressure suction fluid passes to the left through a central bore 262 defined in the number 260, the left end of the bore 262 converging to direct the suction fluid onto a toroidal reversing surface 258a formed on the cone 258. The cone 258 is, of course, suitably supported upon ribs 258b or the like disposed within the converging end portion of the bore 262. The suction fluid is guided by the toroidal surface 258a into a flared passageway 264 defined between the member 260 and the inner surface of the cone 258 with the result that the suction fluid is directed onto the conical mixing surface 260a of the member 260 for mixture with the drive medium entering the passageway 261. The drive medium, of course, mixes with and accelerates the suction fluid to produce a gas and liquid mixture having an intermediate velocity substantially greater than that of the suction liquid but somewhat less than that of the drive medium.

The gas and liquid mixture moves from the conical mixing surface 260e of the mixer 252 onto a toroidal separating surface 260b of the separator 254, which surface causes the drive medium and suction liquid to turn approximately 45 degrees. The centrifugal force causes the higher weight drive liquid to move adjacent the toroidal separating surface 260b to mix with and further accelerate the suction fluid, thereby providing a liquid film adjacent to the toroidal surface. The lighter drive gas is effectively separated from both the drive liquid and suction liquid and forms a gas film on top of this liquid film.

Near the end of the toroidal separating surface 260b, substantially all of the liquidy film flows into the diffuser 256 which is formed by a diffuser element 256:1 cooperating with the member 260 to define a flared passage'having a gradually increasing cross sectional area wherein the dynamic pressure of the liquid film is converted into a static pressure which may be equal t0 or greater than the pressure of the drive medium. The high pressure discharge liquid leaving the diffuser 256 flows to an annular chamber 270 and is delivered through a passageway 272 to a rocket motor or the like. Actually, not all of the separated liquid flows into the diffuser 256 since a small amount is intercepted by the annular knife edge of the diffuser element 256a and is directed into a secondary diffuser 257 defined by the diffuser element 256a and by a secondary diffuser clement 257:1 depending inwardly from the nozzle block 263. Both a small portion of the liquid and a portion of the drive gas located immediately on top of the liquid film are admitted to the secondary diffuser 257. The secondary diffuser elements 256a and 257a cooperate to define a passage of gradually increasing area for expanding the liquid and gas admitted to the secondary diffuser, thereby to provide a low pressure discharge liquid which is passed to a chamber 259 for delivery through a passage 265 to auxiliary equipment utilizing this mixture such as a settling chamber in which the liquid is collected so that it can be returned to the inlet 262. The portion of the gas that is not diverted to the secondary diffuser 257 is intercepted by the annular knife edge of the secondary diffuser element 257@ and is directed into an annular chamber 276 for discharge through a passageway 278 to the atmosphere.

Another embodiment of the jet pump, illustrated in FIG. 21, is identied generally by reference numeral 350 and differs principally from the above described embodiments in that it embodies a combined nozzle-mixer. Only the nozzlemixer arrangement is illustrated and described since it may be used with any of the above described separators and diffusers. Briefly, the nozzle-mixer employed in the pump 350 includes structure for mixing a drive gas and a drive liquid to form a drive medium which y is accelerated along a path converging on a low pressure suction liquid, whereby the medium impinges and mixes with the suction liquid to form a liquid jet surrounded by the drive gas.

Specifically, the drive gas is admitted to the jet pump 350 through a connector 352 and passes through a borre 354 into an annular chamber 356 defined between a manifold sleeve 358 and an inlet tube 360. The chamber 356 connects the bore 354 to an annular chamber 362 which is in communication with a plurality of radially extending passages 364 defined in a houle block 365. The passages 364 communicate at their outer ends with a mixing chamber 366 wherein the drive gas is mixed with a drive liquid. The drive liquid is admitted to the pum-p 350 through a central bore 368 formed in a connector or fitting 370 threadedly attached to the manifold lblock 353. The drive gas passes through the bore 368 into an annular chamber 372 in communication with a chamber 374 which, in turn, opens to a plurality of inclined passages 376 defined in the noule block 365. An annular passageway 37S is provided to connect each of the passages 376 with the mixing chamber 366 in order to introduce a substantially constant amount of drive liquid into the right end of the mixing chamber as viewed in FIG. 2l. By this arrangement, the drive liquid and drive fluid flow `at right angles into one another and are uniformly mixed to provide a drive medium having the shell 382 and the nozzle block 365 are configured to form a converging passage having progressively decreasing cross sectional area for directing the drive medium into a narrow throat. Particularly, the nozzle passage includes a converging portion 33% between its mouth 380a and a throat 380C and a d-iverging portion 380d between the throat 380e` and the circular exit 380e at which the nozzle block 365 terminates. Thus, the drive medium gains a 'high velocity during movement through the nozzle and converges to the left of the exit 380e. An axial bore 386 is defined centrally of the nozzle block 365 in alignment with a similar bore formed in the inlet tube 360 for the purpose of transporting low pressure suction liquid through an opening 387 defined in the manifold block 353 to the nozzle exit 380e. As the suction liquid leaves the left end of the bore 386, it collides with the drive medium issuing from the nozzles exit 380e with the result that the liquid in the drive medium mixes with and accelerates the suction liquid. Actually, an appreciable amount of the drive liquid coalesces with the suction liquid and is separated from the drive gas to form a liquid jet around which is disposed an annular stream of gas. Actual tests reveal that only partial coalescence of the drive liquid occurs and, accordingly, it is necessary that an additional separator such las the type described in the FIG. embodiment must be used.

Anotherembodiment of the jet pump is illustrated in FIG. 30 and is generally similar to the embodiment illustrated in FIG. 20. It differs principally from the FIG. 20 embodiment in that it includes structure for mixi-ng a portion of the high pressure discharge liquid with the suction liquid prior to the mixture of the suction liquid with the drive medium. Moreover, the FIG. 30 embodiment differs from all of the above embodiments in that it works upon the operating cycle shown in FIG. 29 instead of that shown in FIG. l. Briefly, the jet pump includes a nozzle 452 similar to the nozzle unit 52 described above for directing the drive medium into a passage 461 defined between a nozzle block 463 and an end cone 470 and mixer 454, respectively, identical to the cone 258 and the mixer 252 in the FIG. 20 embodiment. The drive medium proceeds, as described above, along the mixer surface 454a to the separator surface 454b where most of the liquid portion is passed into a diffuser 45S and through a chamber 459 and a passageway 460 to a rocket motor. As described above in connection with the FIG. 20 embodiment, some of the liquid portion and some of the gas portion are directed into a secondary diffuser 465 by the knife edge of the diffuser element 458a and thence into a passageway 467, while most of the gas portion is passed into a chamber 472 for discharge through a passage 474 to atmosphere.

The suction liquid flows through a cylindrical conduit into an intermediate chamber 464. The conduit 462 is spaced from the mixing member 454 to define therebetween a passageway 466 which directs a portion of the high pressure discharge fluid from the discharge chamber 459 along the inner surface 454e` of the intermediate chamber 464 for mixing with the suction fluid. By this construction, a portion of the discharge fiuid is fed back into the pump to mix with the suction liquid. thereby to increase the velocity of the suction liquid before it is mixed with the drive medium. The mixed dischargedl liquid and suction liquid enter a reverse annular passageway 473 and are directed onto the mixing surface 454a where the drive medium impnges and mixes with the suction liquid which is. of course, moving at a greater velocity than in the FIG. 20 embodiment. The resultant gas and liquid mixture is then treated as described in the FIG. 20 embodiment.

It will be appreciated that the mixing of the discharge liquid with the suction liquid directs a larger amount of liquid onto the conical surface 454a then is formed on the conical surface 260g of the FIG. 20 embodiment, with the result that the pump shown in FIG. 30 has a 14 lower tiuid friction loss than that shown in FIG. 20. Furthermore, because of the feeding of the high pressure discharge liquid back into the suction liquid chamber, the pump shown in FIG. 30 is capable of pumping a suction liquid having a lower pressure than can be pumped with the pump shown in FIG. 20.

The embodiment of the invention illustrated in FIG. 22 comprises a jet pump 550 which is a modified form of the pump shown in FIG. 20. The jet pump 550 is substantially identical with the structure of the FIG. 20 embodiment with the exception that a mixer 552 embodying a porous wall is substituted for the mixer 252 including the cone 258 and the member 260. More specifically, the jet pump 550 employs a drive nozzle 551 which is identical in construction to the nozzle unit 52 described above and which again performs the functions of mixing a drive gas and a drive liquid and accelerating the resulting drive medium to a high velocity. The right end of the nozzle 551 is supported by a nozzle block 554 and surrounds or encircles the left end of a mixer element 556 comprising a hollow cone having its vertex located centrally within the end of the nozzle 551. The base of the cone 556 is supported by a separator 558 which is mounted on the nozzle block 554. The mixer or cone 556 includes a porous wall having an outwardly facing surface 556a extending across the path of the drive medium and an inwardly facing surface 556b against which the suction liquid impinges. Specifically, the suction fiuid flows through a central, axial bore 560 in the separator 558 into a conical chamber 562 which is defined by the cone 556. The suction liquid is forced, by supplying it at a pressure slightly higher than that at the outer conical surface 556a, to ow from the conical chamber 562 simultaneously through all of the pores in the porous wall into a mixing chamber 563 defined between the cone 556, the nozzle 551 and the nozzle block 554. Due to the large number of pores in the cone 556, mixing of the suction liquid and the drive medium is obtained over substantially the entire surface 556a. A gas and liquid mixture is developed having a velocity slightly less than the velocity of the drive medium.

The gas and liquid mixture leaves the mixer 556 and enters the separator 558. Specifically, the mixture moves along the surface 556a onto a toroidal separator surface 55841 which turns the gas and liquid mixture through approximately 45 degrees. As described above, centrifugal force causes both the drive medium and suction liquid to move toward the toroidal surface in order to separate from the drive gas, thereby forming a liquid film adjacent the surface and a gas stream surrounding the liquid film. As the drive liquid moves adjacent to the toroidal surface 558m it further mixes with and increases the velocity of the suction liquid.

At the end of the toroidal separator surface 558x?, the major portion of the liquid film passes beneath a knifelike flange 564 extending inwardly from the block 554 and is directed into the diffuser 565 defined by the separator 558 and by the flange 564. These elements of the diffuser cooperate to form a flared passage 559 having a gradually increasing cross sectional area wherein the dynamic pressure of the liquid is converted into a static pressure which may be equal to or greater than the drive pressure of the drive medium. The high pressure discharge liquid leaving the diffuser 565- flows into an annular chamber 566 and from there is delivered through a passageway 567 to a rocket motor or the like. Actually, not all of the separated liquid ows into the diffuser 565 since a small amount is intercepted by the annular knife edge of the flange 564 and is directed into the secondary diffuser 568 defined by the iiange 564 and by a second fiange 570 depending inwardly from the nozzle block 554. A portion of the separated liquid and a portion of the drive gas located immediately on top of the liquid film are admitted to the secondary diffuser 568 where they are expanded to provide a low pressure discharge liquid. Sub- 15 l stantially all of the separated gas is intercepted by the annular knife edge of the second flange 570 and is directed into an annular chamber 574 for discharge through a passageway 576 to the atmosphere, the discharge gas being at a low pressure.

A modified form of the embodiment shown in FIGS. 12 to 19 employing a porous wall mixer is illustrated in FIG. 23. A jet pump 650 is there shown which differs principally from the jet pumpv 150 described above in that the solid portion of the inlet 185 defining the conical mixing surface 190 is replaced by a porous wall. More specifically, the jet pump 650 includes an inlet 652 having a bore 654 through which the low pressure suction liquid bows. The suction liquid passes from the bore 654 into a chamber 656 defined within the inlet 652, which chamber communicates with a plurality of spaced inclined passageways 658 in fiuid communication with a chamber 660 defined between a nozzle shell 662 and a porous wall 664. The porous wall is generally frustro conical and is secured at one end to the shell 662 while its other end is secured to the inlet 652 at a location adjacent to a generally toroidal surface 666. The wall includes an outer surface 664er against which the suction liquid mpinges and an inner mixing surface 664b disposed across the path of the plurality of drive medium streams leaving the exits of the plurality of nozzles 668 which are constructed as described above. As described above, the drive medium mixes with the suction liquid to provide a gas and liquid mixture having a velocity slightly less than the drive medium. The mixture leaves the frustro-conical surface 664b and passes onto a toroidal separation surface 666 wherein the liquid and gas are separated and respectively directed into a diffuser and to the atmosphere as described above in connection with the jet pump 150. Yet another embodiment of the present invention is illustrated in FIGS. 24 through 26 and is different from the other embodiments in that it embodies a movable mixer-separator, which is characterized by having lower fiuid friction losses than the stationary separators described above. A jet pump 750 is there illustrated as including a drive nozzle 752 generally similar to the drive nozzle 52 previously described and having a high pressure drive liquid inlet 752a and a high pressure drive gas inlet 752b respectively receiving a drive liquid and a drive gas. The nozzle 752 performs the function of mixing the drive gas and the drive liquid and accelerating the resultant drive medium to a high velocity. The drive medium emerges from the exit 760 of the drive nozzle and enters a mixing chamber 762 defined between a block 763 and a rotatable mixer-separator 754. As is best shown in FIG. 26, the separator 754 comprises a disk 754a having a peripheral flange 7541) which disk 754a is rotatably mounted upon the block 763 by a central hub 756 accommodated within a central axial opening in the block. The drive medium issuing from the nozzle end 760 impinges directly upon the disk 754a and, because the path of the drive medium is angularly related to the disk surface, the separator 754 is rotated at a speed directly proportional to the velocity of the drive medium. Low pressure liquid enters the pump through a conduit 764 which is in communication with the chamber 762 through a passageway 765 defined in the block 763. The outlet 765a of the passageway 765 is spaced slightly behind the nozzle exit 760 so that the suction liquid is drawn through the conduit 764 and onto the rotating disk surface 754a for mixture with and acceleration by the drive medium. The rotating mixerseparator moves the suction liquid underneath the drive medium to provide a gas and liquid mixture. The resulting mixture is moved counterclockwise, as viewed in FIG. 25, and is immediately separated by centrifugal force as the mixer-separator 754 rotates. The liquid portion of the mixture collects on the inner surface of the flange 754b to form a liquid film while the gas forms immediately on top of the liquid film. The liquid film enters a diffuser 768 comprising a diverging slot defined in the block 763 wherein the dynamic pressure of the liquid film is transformed into a static pressure which may be higher than or equal to the pressure of the drive medium. The liquid is discharged from the diffuser 768 into a conduit 770 adapted to be connected to a rocket motor or the like. The gas stream is intercepted by a portion 772 of the block 763 and is directed into a conduit 774 for discharge to the atmosphere as a low pressure discharge gas.

Considering now the embodiment illustrated in FIGS. 27 and 28, there is shown a jet pump 850 differing principally from the other embodiments in that it embodies a separator which does not operate on the principles of centrifugal force. The pump 850 includes a drive nozzle 852, only a portion of which is shown, for producing a drive medium having a high velocity. In this embodiment, the drive medium flows directly into a separator 853 without rst passing through a mixer, the operating cycle for this embodiment being illustrated in FIG. 31. The separator 853 comprises a plurality of aligned plates 854 mounted on three tubes 855 supported at their ends upon a ring 856 threadedly connected to the exit end of the nozzle 852. The plates are spaced equidistantly apart by a plurality of spacers 857 mounted on three spaced rods 858 likewise supported from the ring 856. -The plates 854 are provided at their centers with openings or gates 854a which decrease progressively in size from the entrance end of the separator to the exit end. The drive medium from the nozzle 852 is directed perpendicularly to and along the axes of the plates so as to enter the openings 85411. As the medium progresses through the plates 854 the central portion of the liquid passes through the openings 854a while the outermost liquid portion is deflected inwardly by the converging walls 854b of the openings 854a. However, the gas portion of the stream in traversing the converging opening undergoes a slight rise in pressure and expands radially of the liquid jet with the result that the gas is intercepted by the plates and is exhausted to the atmosphere both downstream and upstream of the openings or gates. This process is repeated at each opening or gate until all or substantiallly all of the gas is removed from the stream and a liquid jet is discharged from the separator.

It will be appreciated that all of the above described embodiments, with the exception of the pumps shown in FIGS. 27 and 30 operate upon the cycle illustrated in FIG. l. In the cycle shown in FIG. 3l for the pump 850, the nozzle 852 feeds a high velocity drive medium comprising a drive gas and drive liquid into a separator 853 which separates the drive gas from the drive fluid at a pressure higher than atmospheric. The drive liquid then fiows through. a second nozzle 904 and then to a mixer 906. The mixer combines the drive uid and suction liquid and feeds the resulting liquid mixture into a diffuser 908. let pumps operating upon the cycle illustrated in FIG. 31 require more drive gas than those operating upon the cycle illustrated in FIG. 1 but it should be appreciated that in the former jet pumps the drive gas is exhausted at sufficient pressure that it has definite utility; for example, the drive gas can be supplied to a rocket motor to add to its thrust or, alternatively, the drive gas can be used to drive another pump.

In the cycle shown in FIG. 32, a nozzle 910 feeds a high velocity drive medium comprising a drive gas and drive liquid into a mixer 912. The mixer 912 mixes the drive medium with the suction liquid and directs the gas and liquid mixture into a first diffuser 914, wherein the mixture is diffused to a high pressure prior to separation of the gas in a separator 916. The liquid separated in the separator 916 is then directed into a second diffuser 918 wherein the dynamic pressure of the liquid is transformed into a static discharge pressure.

The cycle shown in FIG. 33 is similar to that shown in FIG. 32 but differs therefrom in that a condenser 924 is substituted for the first diffuser 914. In those jet pumps operating upon the FIG. 33 cycle it is possible to use, in a more eicient manner than in the jet pumps operating on the cycles of FIGS. 1, 29, 31 and 32, a drive gas which partially condenses when mixed with the suction liquid since the condenser liquees the condensible portion of the drive gas and permits it to ow through the diffuser rather than being exhausted from the separator.

It should be noted that the gaseous portion of the drive mixture has a much smaller mass than the liquid portion. Consequently, in those pumps wherein the mixer and the separator are both at substantially the same pressure, as in the pumps operating on the cycles of FIGS. 1, 29 and 33, the separator can be placed upstream of, or combined with, the mixer without substantially reducing the velocity imparted to the suction liquid and, hence, without greatly reducing the eiiiciency of the pump.

While the present invention has been described in connection with the details of particular embodiments thereof, it should be understood that these details are not intended to be limitative of the invention since many modications will be readily apparent to those skilled in this art and it is, therefore, contemplated in the accompanying claims to cover any such modications as fall within the true spirit and scope of the invention.

What is claimed as new and desired to be secured by United States Letters Patent is:

l. A pump for increasing the pressure of a low pressure liquid comprising means for mingling a high pressure drive gas and a high pressure drive liquid, mixing means connected to receive said mingled high pressure drive gas and liquid for mixing said low pressure liquid with said mingled high pressure drive gas and liquid in order to develop a moving gas-liquid mixture, means connected lto receive said mixture for separating the gas portion from the liquid portion of said mixture, and means connected to receive the liquid portion of said mixture for converting the dynamic pressure of said liquid portion to a static pressure which is higher than the pressure of the low pressure liquid.

2. A pump for increasing the pressure of a low pressure liquid comprising means for mingling a high pressure gas and a high pressure liquid to produce a mingled fluid, means connected to receive said mingled uid for expanding said mingled iiuid to increase its velocity, mixing means connected to receive said mingled uid and said low pressure liquid for mixing the mingled uid and the low pressure liquid to develop a gas-liquid mixture having a velocity greater than that of the low pressure fluid, separating means connected to receive said mixture for separating said mixture into liquid and gas components and means connected to receive said liquid component for converting the dynamic pressure of the separated liquid component to a static pressure which is higher than that of the low pressure liquid.

3. A pump for increasing the pressure of a low pressure liquid comprising drive nozzle means for combining a high pressure gas from a high pressure source and a high pressure liquid from a discharge port of the pump, mixing means connected to receive the combined uid for mixing the combined fluid and the low pressure liquid thereby to develop a liquid gas mixture having a velocity greater than that of the low pressure liquid, separating means connected to receive said mixture for separating said mixture into gas and liquid components, means connected to said separating means for discharging the gas component to atmosphere, means connected to receive said liquid component for converting the dynamic pressure of the liquid component to a static pressure, means communicating with the last-mentioned means for discharging said liquid component through the discharge port of the pump, and means communicating with the last-mentioned means for feeding back to said drive nozzle means a portion of said liquid component.

4. A pump for increasing the pressure of a low pressure liquid comprising means for admitting a high pressure liquid into the pump, means for admitting a high pressure gas into the pump, said liquid and gas combining in said pump to produce a drive fluid, means connected to receive said drive uid and said low pressure liquid for mixing said drive iiuid and said low pressure liquid to produce a mixed i'luid, separating means cornmunicating with the last-named means for separating said mixed uid by centrifugal force to develop liquid and gas components, means communicating with the lastnamed means for discharging the gas component to the atmosphere, means communicating with said separating means for decelerating the liquid component to convert its dynamic pressure to a static pressure for discharge from said pump, and means communicating with the lastnamed means for feeding back a portion of said liquid component into said pump to be combined with said high pressure gas.

5. A pump for increasing the pressure of a low pressure liquid comprising means for mingling a high pressure liquid developed by the pump and a high pressure gas developed by a high pressure source to produce a drive uid, means connected to receive said drive fluid for expanding said drive fluid to accelerate it to a high velocity, means communicating with said high velocity drive uid and said low pressure liquid for increasing the velocity of said low pressure liquid by mixing it with said drive uid to produce a gas and liquid mixture, separating means connected to receive said mixture for separating the gas in the mixture from the liquid, first means communicating with said separating means for discharging the separated gas to atmosphere, second means communicating with said separating means for decelerating the separated liquid to convert its dynamic pressure to a static pressure higher than the pressure of the low pressure liquid, and means connected to the last-named means for feeding back to said pump a portion of the decelerated liquid for mingling with said high pressure gas.

6. A pump for increasing the pressure of a low pressure liquid comprising means for mingling a high pressure drive gas and a high pressure drive liquid to develop a drive fluid, said means having a first inlet through which said drive gas passes and a second inlet through which said drive liquid passes, means connected to re- A ceive said drive fluid for expanding said drive tiuid to a pressure approximately equal to the pressure of the low pressure liquid in order to accelerate the drive uid, means connected to receive said expanded drive uid for mixing said drive uid and said low pressure liquid to produce a gas-liquid mixture having a velocity greater than the velocity of said low pressure liquid, means connected to receive said mixture for separating the mixture into gas and liquid components, means connected to the last-mentioned means for exhausting the gas component from said pump, means connected to receive said liquid component for converting the dynamic pressure of the liquid component to a static pressure higher than the pressure of said low pressure liquid, means connected to the last-mentioned means for discharging the liquid component from said pump, and means connected to the lastmentioned means for delivering a portion of the discharged liquid component to said second inlet to provide a feedback connection.

7. In a pump for increasing the pressure of a low pressure liquid, the combination of a drive nozzle for mingling a high pressure drive gas and a high pressure drive liquid and expanding the mingled drive gas and drive liquid to a pressure approximately equal to said loW pressure liquid, said drive nozzle having first and second inlets for respectively receiving said drive gas and drive liquid, a mixer connected to said drive nozzle for mixing the mingled drive gas and drive liquid with said low pressure liquid to provide a gas-liquid mixture, a separator connected to receive said mixture for separating the gas and liquid components of the mixture, means connected to said separator for exhausting the separated gas component from said pump, a diffuser connected to said separator for converting the dynamic pressure of the liquid component to a static pressure higher than the pressure of said low pressure liquid, means communicating W1th said diffuser for conducting a portion of the converted liquid component to said second inlet, and a port communicating with said diffuser for discharging said liquid component under static pressure from said pump.

8. The pump of claim 7 wherein said separator includes a curved member against which said gas-filled mixture is directed and by which said gas and liquid components are separated by centrifugal force.

9. A jet pump for increasing the pressure of a low pressure liquid, said pump comprising means for mingling a high pressure drive gas and a high pressure drive liquid to develop a drive medium, mixer means connected to receive at least a portion of said mixture and provided with a porous wall having first and second opposed surface portions, means communicating with the last-mentioned means for directing said low pressure liquid against said second surface portion, said wall being disposed to intercept at least a portion of said drive medium and to permit said portion to move over said first surface portion, said low pressure liquid passing through said porous wall for mixture with said portion of said drive medium and means connected to receive at least said drive medium for separating the gas component from the liquid component.

10. A jet pump for increasing the pressure of a low pressure liquid, said pump comprising means for mingling a high pressure drive gas and a high pressure drive liquid to form a drive medium, mixer means connected to receive said drive medium and said low pressure liquid provided with a porous wall including a first surface over which said drive medium passes and further including a second surface exposed to said low pressure liquid, the passage of said drive medium over said first surface at a low pressure causing said low pressure liquid to be drawn through said porous wall to be mixed with said drive medium in order to form a gas-liquid mixture, and means communicating with said mixer means for separating the gas and liquid components of said mixture.

1l. The pump of claim 9 wherein said porous wall comprises a generally conical configuration having an apex disposed in the path of flow of the drive medium.

12. The pump of claim 9 wherein the separating means includes a generally frustro-conical member having a wall portion of convex cross section, one end of the wall portion being contiguous with the porous wall of said mixer means to provide a surface over which passes the mixture of the drive medium and the low pressure liquid.

13. In a pump for increasing the pressure of a low pressure liquid by using a drive fluid, mixing means for mixing said low pressure liquid into a moving stream of drive fluid comprising a' porous member having first and second opposed surfaces, means communicating with the first-mentioned means for directing said stream of drive fluid to move tangentially over the first surface, and means communicating with said first-mentioned means for exposing said low pressure fluid to said second surface so that said low pressure fluid passes through the porous Wall to mix with the drive fluid passing over the first surface.

14. The mixing means of claim 13 wherein said porous member includes a generally hollow conical structure having a porous wall, the apex of the conical structure being located in the middle of the drive fluid stream.

l5. Apparatus for increasing the pressure of a low pressure liquid comprising means for directing said low pressure liquid against a surface of a porous wall, means for passing a drive uid including a gas component over the opposite surface of the porous wall to cause the low pressure liquid to be passed through the porous wall for mixture with the drive liuid, and means connected to receive the resultant mixture for separating from the resulting mixture the gas component of the drive uid.

16. The jet pump of claim 1 wherein the drive gas and liquid and the low pressure liquid are supplied to the mixing means along substantially parallel paths and wherein the separating means includes means for separating said mixture into a high pressure discharge liquid and a low pressure discharge liquid.

17. The jet pump of claim l wherein there is additionally provided means communicating with said mixing means for mingling a part of the converted liquid portion of the mixture with the low pressure liquid before the low pressure liquid is mixed with the drive gas and liquid.

18. The jet pump of claim 1 wherein the mixing means includes structure for moving said low pressure liquid in a stream along a predetermined path and additional structure for guiding said mingled drive gas and liquid in a stream converging toward the predetermined path whereby said streams are combined to form a liquid jet stream surrounded by said drive gas.

19. The jet pump of claim 1 wherein the separating means comprises a member having a toroidal surface on which said low pressure liquid and mingled drive gas and v liquid are directed, a portion of said surface converging to an apex for forming a liquid jet surrounded by the drive gas.

'20. The jet pump of claim 19 wherein the mixing means includes a porous wall having a surface portion contiguous with the toroidal surface, said porous wall being exposed to the low pressure liquid which passes through the wall to mix with the drive gas and liquid passing over said surface portions of said porous wall.

21. The jet pump of claim 1 wherein the mixing means includes a movable surface against which the drive gas and liquid impinges so that said surface is moved at a velocity substantially equal to the velocity of the drive gas.

22. The jet pump of claim l wherein the separating means includes a plurality of plates having concentric progressively smaller openings therein through which pass the drive gas and liquid and the low pressure liquid.

23. The jet pump of claim l wherein said mingling means includes means defining spaced first and second chambers, means defining a plurality of spaced conduits located in an intermediate chamber and connected between said first and second chambers, one end of each of said conduits being supported in airtight relation with a wall of said first chamber and the other end of each conduit extending into said second chamber, means providing fluid communication between said intermediate chamber and said second chamber, said drive liquid passing from said first chamber through said conduits into said second chamber and said drive gas passing from said intermediate chamber through the fluid communication means into said second chamber for mixture with said drive liquid.

24. A pump for increasing the pressure of a low pressure liquid comprising means for mingling a high pressure drive gas and a high pressure drive liquid, mixing means connected to receive said mingled high pressure drive gas and liquid for mixing said low pressure liquid with said mingled high pressure drive gas and liquid in order to develop a moving gas-liquid mixture, means connected to receive at least said mingled drive gas and liquid for separating the gas from the liquid, and means connected to receive the liquid portion of said mixture for converting the dynamic pressure of said liquid portion of the mixture to a static pressure which is higher than the pressure of the low pressure liquid.

25. A pump for increasing the pressure of a low pressure liquid comprising means for mingling a high pres- 21 22 sure drive gas and a high pressure drive liquid, means ing the gas from the liquid, and means connected to reconnected to receive at least said high pressure drive ceive the liquid portion of said mixture for converting liquid for mixing said low pressure liquid with at least the dynamic pressure of said liquid portion to a static said high pressure drive liquid in order to develop at least pressure which is higher than the pressure of the low a moving liquid mixture, means connected to receive at 5 Vpressure liquid. least said high pressure `drive gas and liquid -for separat- No references cited.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent N0. 3,031,977 May 1 1962 David G. Elliott It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 19, line ll, for "gas-filled" read gas liquid Signed and sealed this 21st day of August 1962.

(SEAL) Attest:

ESTON G JOHNSON DAVID L LADD Attcsting Officer Commissioner of Patents 

